Britz...believe your friend when she tells you that things have been a blur and she honestly can't remember conversations and events that have happened. In the midst of a major episode (like what is sounds like your friend is going thru right now) it is ALL we can do to keep ourselves alive. EVERYTHING becomes 100 times more difficult.
I can totally understand your point about her illness being all she talks about and you not wanting to listen any more, but it is actually a VERY good sign that she IS doing this. This tells me that she is in the state of mind that she wants to do everything she can to understand herself and her disease. There are SO MANY bipolars who don't even take time to learn what it means to be bipolar...so this is a very good sign indeed - annoying to outsiders, but it means she will have a much more stable and happier future and that your friendship will actually stand a chance in the future.
I did the same thing to my best friend and eventually she stopped talking to me nearly completely - now we only e-mail a few times a year and I feel betrayed by her.
It sounds like your friend is doing absolutely EVERYTHING she possibly can to triumph over the difficult hand she has been dealt. Every minute of everyday is filled with thoughts of her illness and how to cope...so naturally, she doesn't have much else on her mind. This illness (when dealing with a major episode) is totally consuming AND disabling.
Try not to judge HER, but rather know that it is her ILLNESS that has brought on all these changes. It is no different than if she had a potentially terminal form of cancer and each of her days was filled with chemo and doc visits and physical exhaustion and lots of fighting....it really is the much the same.
Be there for your friend, in spirit at least if you can't be there for her emotionally or anything else right now. Tell her that you realize she is going through something that you can't possibly imagine or understand right now and that what you do understand is that she is trying her damnedest to make it through. Tell her that it will be more beneficial for her to talk to the other woman (who can truely understand what it's like) while she's going through this because you don't know how to help her....but that you will always be her friend and that your friendship will be waiting when she comes back to being herself. And she will come back Britz....I promise this...and she will likely be an even better friend and person for all she's endured and made it through.
In otherwords....continue loving your friend from a distance until the time comes when you can come back to the close friendship you both enjoyed for so many years. Remember she needs all the support she can get right now and if you desert her right now...it will have a very major and very negative impact on her recovery. She needs to know you love and care about her, even if you can't give anything to her right now.